Americans, we are often reminded, face an obesity epidemic of epic proportions: Over a third of US adults are certifiably obese, and another third are overweight.

But a team of health researchers has begun to argue that the terms "overweight" and "obese" actually miss the point, obscure the real scale of the problem, and even get in the way of fixing it.

The reason, they say, is that obesity-related health risks don’t actually depend on how much you weigh. The real question is how much of that weight comes from body fat, especially around the midsection.

“We’ve all been getting this wrong from the get-go,” said Paul Laursen, adjunct professor at the Auckland University of Technology. “What matters is your abdominal fat. And we should be measuring what matters.”

In other words, a person whose body weight is “normal” might have enough excess abdominal fat on his or her body to create health risks, while other people — in particular, athletes — might be technically “overweight” by standard measurements, but much healthier.

Laursen and his colleagues want everyone — doctors, nutritionists, and the rest of us — to start using a new word he says more accurately describes the problem: overfat.

Rather than thinking of these disorders as separate, individual clinical problems, it might be best to consider the relationships between overfat, its various risks, and its associated downstream diseases as a spectrum or progression where the vicious cycle of overfat, insulin resistance, and chronic inflammation lies at one end, (constituting the population with early measurable abnormality), while the presence of chronic conditions resides at the other end. |
Maffetone, Rivera-Dominguez, and Laursen.

Words matter, Laursen and his colleagues argue, because they can impact how people think about a problem, and what they do about it.

“People say, ‘Oh, I’ve got to lose some weight,’” Laursen said. “Well, there are loads of ways you can lose weight. You can lower your bone density. Or you can lose water weight. There are all these different ways. But, really, you don’t want to just lose weight. You want to lose fat.”

Laursen and his colleagues take aim at the concept of Body Mass Index, or BMI, the standard method for determining whether someone is overweight or obese.

BMI is calculated by dividing a subject’s weight in kilograms by their height in meters squared. A result between 25 and 30 is overweight, and anything over 30 is obese.

But this system has long been understood by health professionals to be a crude metric at best. The US Centers for Disease Control and Prevention warns that “BMI can be used as a screening tool but is not diagnostic of the body fatness or health of an individual.”

The problem is that BMI doesn’t care where the weight comes from. Judging strictly by BMI, many top athletes in prime physical form are overweight — an absurd result given their low levels of body fat. Laursen, a lean former competitive triathlete, said his own BMI has ranged above 25.

So who’s overfat? And how can you tell?

Laursen and his colleagues define the term as the state of having an excess amount of body fat sufficient to impair health.

And they propose a simple method for testing it. Just measure your waist at the level of the belly button. Then check whether that equals more than half your height.

Unfortunately, by that standard, many of us are overfat — considerably more than would be considered overweight or obese.

When Laursen and his colleagues Philip Maffetone and Ivan Rivera-Dominguez first wrote about the concept in January this year, they estimated that somewhere between 62 percent and 76 percent of the world population might be overfat.

But in a new study, the team looked at the populations of 30 advanced countries to arrive an even more alarming statistic.

In the United States and other advanced countries like New Zealand and Iceland, 90 percent of adult males and 50 percent children may suffer from being overfat, they wrote in an article published in the journal Frontiers in Public Health. Eighty percent of adult women in the US are overfat.

What’s more, while it may appear that the number of people who are overweight or obese is leveling off in some developed countries, “the overfat pandemic continues to grow,” they wrote.

This new research into the scale of the problem follows the team’s warning from their earlier paper in January: “The well-documented obesity epidemic may merely be the tip of the overfat iceberg.”